Performance Evaluation of Reinforced concrete Bridges without Plans: A case study on the assessment of Koka Bridge
No Thumbnail Available
Date
2019-06-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
In Ethiopia, reinforced concrete bridges that were constructed in the early and mid
of 20
th
century exist in large numbers and are still in service. Due to the changing
nature of vehicular load supported by these bridges and frequent permit trucks
using the bridges, assessment of bridges to obtain their load carrying capacity is
usually desired. The legal owner of the bridges, the Ethiopian Roads Authority,
cannot provide necessary information such as as-built drawings, and properties of
construction materials.
The thesis demonstrates the assessment of load carrying capacity of old and
deteriorated reinforced concrete bridges without plans (as built drawings or design
drawings). Assessment codes give sufficient recommendations on how to load rate
bridges that does not have sufficient data to be used in load rating. The safe live load
carrying capacity of a highway structure is known as its rating.
A case study has been conducted on one of the bridges along the heavily loaded
route corridors bridges i.e. Koka River Bridge. Data obtained from historical records,
field inspection and measurement besides design code existing by the time of
construction of the bridge, 1953 G.C. has been used to prepare an effective Finite
Element model on Abaqus/CAE 6.13-1. A moving tire load on the bridge deck has been
used for the analysis, and the results obtained have been used to load rate the
bridge for a permit load and ERA’s legal loads.
The bridge was found to have sufficient capacity to withstand Legal loads and
selected permit load, it has 50% and 8% reserve capacity respectively. However, it is
recommended to maintain defects and distresses noticed on field inspection since
they might lead to further deterioration of the bridge.
Description
Keywords
Bridges, Reinforced concrete, load rating, FEM